Means for expanding pistons



March 19 40. A. WIEBKE 2,194,778 MEANS FOR EXPANDING PISTONS Filed Jan.11, 1937 4 7&4 INVENTOR.

WM BY 26 27 Patented Mar. 26, 1940 PATENT OFFICE 7 2,194,778 MEANS FOREXPANDING rrs'rons August Wiebke, Los Angeles, Calit, assignor to TheHastings Manufacturing Company,

Hastings, Mich, a corporation of Michigan Application January 11, 1937,Serial No. 120,028

1, Claim.

My invention relates to means for expanding pistons for the purpose ofmaking a better fit and eliminating lateralmovement or piston slap inthe cylinder with its attendant noise and faulty operation.

My invention is adapted for usein expanding pistons of all kinds, thatis: ribbed pistons, cast iron pistons, steel and other metal pistons,and is applicable to thediiierent parts of the piston so as to expandthe piston where needed and to do it under the eye and control of theoperator of the machine.

Among the salient objects of my invention are: to provide a means andmethod for expanding pistons which is simple,economical, eflicient andwhich is under" the fullest control of the operator; to provide'in aninvention of the character referred to means which can be directlyapplied to any part of a piston and operated to produce any degree orarea of expansion. needed to put the piston innormal condition; to pro-'vide in an invention of the character referred to means for applying toany part of a piston a hammering process of such rapidity and shortnessof stroke that it is practically a continuous application of blows orpressures to the surface being treated, as distinguished from blowswhich leave individual indentations which are clearly visible, in otherwords, applicants means produces a smooth surface something after themanner of a rotary planer, the strokesbeing so rapid and uniform thatthere is no visible individual indent or depression.

In order to more fully explain invention, 1 have illustrated on theaccompanying sheet of drawings one practical means for carrying out mynew methodofexpanding pistons and the like, which I will now describe.

Figure 1 is a side elevation of a machine embodying my invention;

Figure 2 isa vertical sectional View taken on line 2-2 on Fig. 1; t

Figure 3 is a sectional view taken on line 3-3 on'Fi 1; 1*

Figure 4 is a plan view, partly in section on line i l of Fig. 2;' andFigure 5 is a view of a piston, showing the hammer in place andindicating the expansion resulting from the action of the hammer.

Referring now in detail to the drawing, suitable supporting legs, as 6and 'l are provided for supporting the mechanisrmthe legs 1, 7,supporting an electric motor M, the shaft of which is designated 8, andhas two universal joints, 9, 9, therein, said shaft 8 having at itsoperating end (or. 78-F-13) an eccentric camelement it, supportedbetween i the sides H, II, on the upper end of an adjustable bracket H,having a slot l2 therein,

through which a screw bolt l3 holds said bracket to the bodyor framestructure 6., 6f, above the legs 6, 6, as seen in Figs. 1 and 2. Anadjustment screw hi operates in the lower end of said I bracket ii, andis anchored ina lugextension i5, on the bodyfi, and is provided with anoperating hand wheel it at its lower end, whereby the operation of. saidhand wheel iii and said screw i4, raises and lowers said bracket ii.

Pivotally mounted in the upper; end of said adjustable bracket Ii,between the sides H, H,

thereof is a hammer operating lever H, the outer end of which underliessaid eccentric cam element I0 and is intermittently depressed thereby assaid cam element is rotated by said motor shaft 8. On the underside ofthe upper ,end of said adjustable bracket is a downwardly extendingtubular portion H8, in which is mounted a plunger I9, normally pressedupwardly by a I 23 is anchored in the end of said lever I! by its shankportion 23' on which is screwed a nut 24, as indicated in Fig. 5. Saidhammer element 23 can thus be adjusted verticallyup and down coiledspring Zll, the tensionof which is reguf lated by a screw bolt 2 I, withlock nut 22 thereon,

n ismounted,

within a piston, indicated C, as, illustrated in the drawing;

The upper end of said body or frame structure 6', 6', constitutes ananvil 25, upon which the cylinder or piston C is to beheld fortreatment, asindicated'. Slidably mounted on said body at opposite sidesof the anvilportion are two piston holding members 26, 26, connected byan operating screw 21, having right and left hand threads thereon, andoperable by means of a positions by means of a thumb screw held in thehand of the operator and turned on the anvil during the operation. Thismember 30 is an adjustable stop against which the head of the piston Cabuts as it is held in position.

The anvil portion of the top has at its opposite sides two extensions,as 25, 25', and it is upon and between these extensions that the pistonholding members 26, 26, are movably held, a neck portion 2.6 extendingdown between said arms or extensions 25', 25', as seen in Fig. 4.

In Fig. is shown a representation of a piston 0, showing the hammerelement 23 in place therein, above the anvil 25, the short arrows AA andBB indicating areas which have had the treatment with the hammer, whilethe light broken lines indicate the expansion caused in the piston wallas a result of such treatment. It is understood that the piston wears onthe sides opposite each other and at right angles to the sides on whichthe crank pin bearings are formed, and the operation of the hammerelement in the manner herein provided for operates to compress thematerial in the area being treated so as to cause expansion at theopposite sides from the area being treated.

It is to be understood that this operation is diiferent from so calledpeening operation in which the hammer used has a round or pointed endand causes a corresponding expansion of the metal in all directions.Applicants hammer is long and its operation is more like swaging ,forthe expansion is in opposite directions, circumferentially .01" thepiston. The piston is held in place on the anvil and-is turned back andforth by hand as the hammer is operated at a Very high rate of speed, sothat the swaging action or treatment is applied uniformly to theparticular area, or to a rib, inside of the piston and in such manner asto produce the desired expansion in the desired place or area on thepiston;

The hammer element 23, it is to be noted, is elongated so as to have awork edge extending axially of the piston and action is more of aswedging action and the metal is compressed immediately above the anviland expansion caused circumferentially in opposite directions from thearea being subjected to the vibrating hammering action or treatment.This vibratory action is such that the surface contacted, as the pistonis rotated back and forth by hand, is uniformly compressed and noindividual indentations are visible. I have found this method mosteffective and successful in expanding pistons as and Where needed,regardless of the type or material of the piston.

While I have shown and described one practical means for expandingpistons, I am aware that many changes in the details of construction andarrangement can be made without departing from the spirit of theinvention and I do not, therefore, limit the invention to the showingmade, except as I may be limited by the hereto appended claim.

I claim:

In a machine for expanding pistons, in combination with an anvil, ahammer supporting member adjustable up and down relative to said anvil,a hammer-operating lever pivotally supported intermediate its ends onsaid hammer supporting member, a hammer element on one end of saidlever, a motor-operated eccentric cam rotatably mounted in said hammersupporting member and positioned to intermittently depress and releasethe other end of said lever, a spring-actuated plunger carried by saidhamrner supporting member and acting against the under side of the endof said lever in opposition to the action or" said eccentric cam, meansfor regulating the tension of the spring actuating said plungen'andscrew means for adjusting said hammer supporting member and said hammeractuating mechanism as a unit relative to the anvil.

AUGUST WIEBKE.

